#!/bin/bash
#  _____               _           _
# |   __|___ ___ ___ _| |___ _____| |_ ___ ___ ___
# |   __|  _| -_| -_| . | . |     | . | . |   | -_|
# |__|  |_| |___|___|___|___|_|_|_|___|___|_|_|___|
#
#                              Freedom in the Cloud
#
# koel application
# https://gist.github.com/bplower/613a99156d603abac083
#
# License
# =======
#
# Copyright (C) 2017-2018 Bob Mottram <bob@freedombone.net>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

VARIANTS='full full-vim media'

IN_DEFAULT_INSTALL=0
SHOW_ON_ABOUT=1

KOEL_DOMAIN_NAME=
KOEL_CODE=
KOEL_ONION_PORT=8118
KOEL_PORT=9002
KOEL_REPO="https://github.com/phanan/koel"
KOEL_COMMIT='8e9b021aa09f2b1460977bdd52fff14ea2bc1607'
KOEL_ADMIN_PASSWORD=

KOEL_SHORT_DESCRIPTION=$'Koel music'
KOEL_DESCRIPTION=$'Koel music player'
KOEL_MOBILE_APP_URL=

koel_variables=(ONION_ONLY
                KOEL_DOMAIN_NAME
                KOEL_CODE
                DDNS_PROVIDER
                MY_EMAIL_ADDRESS
                MY_USERNAME)

function logging_on_koel {
    echo -n ''
}

function logging_off_koel {
    echo -n ''
}

function koel_remove_gravatar {
    cd "/var/www/${KOEL_DOMAIN_NAME}/htdocs" || exit 8345374534
    sed -i "s|www.gravatar.com|${KOEL_DOMAIN_NAME}|g" node_modules/browser-sync-ui/public/js/app.js.map
    sed -i "s|www.gravatar.com|${KOEL_DOMAIN_NAME}|g" public/js/app.*.js
    if ! grep -q "//Vue.set(user, 'avatar'" resources/assets/js/stores/user.js; then
        sed -i "s|Vue.set(user, 'avatar'|//Vue.set(user, 'avatar'|g" resources/assets/js/stores/user.js
    fi
}

function remove_user_koel {
    remove_username="$1"

    "${PROJECT_NAME}-pass" -u "$remove_username" --rmapp koel
}

function add_user_koel {
    new_username="$1"
    new_user_password="$2"

    "${PROJECT_NAME}-pass" -u "$new_username" -a koel -p "$new_user_password"
    echo '0'
}

function install_interactive_koel {
    if [ ! "$ONION_ONLY" ]; then
        ONION_ONLY='no'
    fi

    if [[ $ONION_ONLY != "no" ]]; then
        KOEL_DOMAIN_NAME='koel.local'
    else
        KOEL_DETAILS_COMPLETE=
        while [ ! $KOEL_DETAILS_COMPLETE ]
        do
            data=$(mktemp 2>/dev/null)
            if [[ "$DDNS_PROVIDER" == *"freedns"* ]]; then
                dialog --backtitle $"Freedombone Configuration" \
                       --title $"Koel Configuration" \
                       --form $"\\nPlease enter your Koel details. The background image URL can be left blank.\\n\\nIMPORTANT: This should be a domain name which is supported by Let's Encrypt:" 16 65 3 \
                       $"Domain:" 1 1 "$(grep 'KOEL_DOMAIN_NAME' temp.cfg | awk -F '=' '{print $2}')" 1 25 33 40 \
                       $"Code:" 2 1 "$(grep 'KOEL_CODE' temp.cfg | awk -F '=' '{print $2}')" 2 25 33 255 \
                       2> "$data"
            else
                dialog --backtitle $"Freedombone Configuration" \
                       --title $"Koel Configuration" \
                       --form $"\\nPlease enter your Koel details. The background image URL can be left blank.\\n\\nIMPORTANT: This should be a domain name which is supported by Let's Encrypt:" 16 65 3 \
                       $"Domain:" 1 1 "$(grep 'KOEL_DOMAIN_NAME' temp.cfg | awk -F '=' '{print $2}')" 1 25 33 40 \
                       2> "$data"
            fi
            sel=$?
            case $sel in
                1) rm -f "$data"
                   exit 1;;
                255) rm -f "$data"
                     exit 1;;
            esac
            KOEL_DOMAIN_NAME=$(sed -n 1p < "$data")
            if [ "$KOEL_DOMAIN_NAME" ]; then
                if [[ "$KOEL_DOMAIN_NAME" == "$HUBZILLA_DOMAIN_NAME" ]]; then
                    KOEL_DOMAIN_NAME=""
                fi
                TEST_DOMAIN_NAME=$KOEL_DOMAIN_NAME
                validate_domain_name
                if [[ "$TEST_DOMAIN_NAME" != "$KOEL_DOMAIN_NAME" ]]; then
                    KOEL_DOMAIN_NAME=
                    dialog --title $"Domain name validation" --msgbox "$TEST_DOMAIN_NAME" 15 50
                else
                    if [[ "$DDNS_PROVIDER" == *"freedns"* ]]; then
                        KOEL_CODE=$(sed -n 2p < "$data")
                        validate_freedns_code "$KOEL_CODE"
                        if [ ! "$VALID_CODE" ]; then
                            KOEL_DOMAIN_NAME=
                        fi
                    fi
                fi
            fi
            if [ $KOEL_DOMAIN_NAME ]; then
                KOEL_DETAILS_COMPLETE="yes"
            fi
            rm -f "$data"
        done

        # save the results in the config file
        write_config_param "KOEL_CODE" "$KOEL_CODE"
    fi
    write_config_param "KOEL_DOMAIN_NAME" "$KOEL_DOMAIN_NAME"
    APP_INSTALLED=1
}

function change_password_koel {
    curr_username="$1"
    new_user_password="$2"

    read_config_param 'KOEL_DOMAIN_NAME'

    "${PROJECT_NAME}-pass" -u "$curr_username" -a koel -p "$new_user_password"
}

function koel_create_database {
    if [ -f "$IMAGE_PASSWORD_FILE" ]; then
        KOEL_ADMIN_PASSWORD="$(printf "%s" "$(cat "$IMAGE_PASSWORD_FILE")")"
    else
        if [ ! "$KOEL_ADMIN_PASSWORD" ]; then
            KOEL_ADMIN_PASSWORD="$(create_password "${MINIMUM_PASSWORD_LENGTH}")"
        fi
    fi
    if [ ! "$KOEL_ADMIN_PASSWORD" ]; then
        return
    fi

    function_check create_database
    create_database koel "$KOEL_ADMIN_PASSWORD" "$MY_USERNAME"
}

function reconfigure_koel {
    echo -n ''
}

function koel_import_from_directory {
    read_config_param MY_USERNAME

    data=$(mktemp 2>/dev/null)
    dialog --title "Choose a directory containing music" --dselect "/home/$MY_USERNAME/" 30 60 2> "$data"
    selected_dir=$(cat "$data")
    rm -f "$data"
    if [[ "$selected_dir" == '/music' ]]; then
        return
    fi
    if [ ! -d "$selected_dir" ]; then
        return
    fi
    if [[ "$selected_dir" == "/home/$MY_USERNAME/" ]]; then
        return
    fi
    if [[ "$selected_dir" == "/home/$MY_USERNAME/."* ]]; then
        return
    fi
    if [[ "$selected_dir" == *"/Maildir" || "$selected_dir" == *"/Sync" ]]; then
        return
    fi

    dialog --title $"Import music directory" \
           --backtitle $"Freedombone Control Panel" \
           --defaultno \
           --yesno $"\\nImport the directory:\\n\\n  $selected_dir" 12 75
    sel=$?
    case $sel in
        1) return;;
        255) return;;
    esac

    # shellcheck disable=SC2086
    mv $selected_dir /music

    dialog --title $"Import music directory" \
           --msgbox $"Import success. You may need to re-sync within Koel." 6 40
}

function koel_import_from_usb {
    clear
    detect_usb_drive

    if [ ! -b "$USB_DRIVE" ]; then
        dialog --title $"Import music from USB drive" --msgbox $'No USB drive found' 6 50
        return
    fi

    backup_mount_drive "${USB_DRIVE}"
    if [ ! -d "$USB_MOUNT/Music" ]; then
        dialog --title $"Import music from USB drive" --msgbox $'No Music directory found on USB drive' 6 50
        backup_unmount_drive "${USB_DRIVE}"
    fi
    cp -ru "$USB_MOUNT/Music/"* /music
    backup_unmount_drive "${USB_DRIVE}"
    dialog --title $"Import music from USB drive" --msgbox $'Import complete. You may now remove the USB drive' 6 50
}

function koel_export_to_usb {
    clear
    detect_usb_drive

    if [ ! -b "$USB_DRIVE" ]; then
        dialog --title $"Export music to USB drive" --msgbox $'No USB drive found' 6 50
        return
    fi

    backup_mount_drive "${USB_DRIVE}"
    if [ ! -d "$USB_MOUNT/Music" ]; then
        mkdir -p "$USB_MOUNT/Music"
    fi
    cp -ru /music/* "$USB_MOUNT/Music"
    backup_unmount_drive "${USB_DRIVE}"
    dialog --title $"Export music to USB drive" --msgbox $'Export complete. You may now remove the USB drive' 6 50
}

function format_music_drive {
    detect_usb_drive
    dialog --title $"Format USB drive $USB_DRIVE for music storage" \
           --backtitle $"Freedombone Control Panel" \
           --defaultno \
           --yesno $"\\nPlease confirm that you wish to format drive\\n\\n    ${USB_DRIVE}\\n\\nAll current data on the drive will be lost, and you will be prompted to give a password used to encrypt the drive.\\n\\nDANGER: If you screw up here and format the wrong drive it's your own fault!" 16 60
    sel=$?
    case $sel in
        1) return;;
        255) return;;
    esac

    clear
    echo ''
    echo $"Formatting drive $USB_DRIVE. ALL CONTENTS WILL BE LOST."
    echo ''
    "${PROJECT_NAME}-format" "$USB_DRIVE"
    dialog --title $"Format USB drive $USB_DRIVE for music storage" --msgbox $'Format complete. You may now export music or remove the USB drive' 6 50
}


function configure_interactive_koel {
    W=(1 $"Import music from directory"
       2 $"Import music from USB drive"
       3 $"Export music to USB drive"
       4 $"Format a USB drive for music storage")

    while true
    do
        # shellcheck disable=SC2068
        selection=$(dialog --backtitle $"Freedombone Administrator Control Panel" --title $"Koel" --menu $"Choose an operation, or ESC to exit:" 12 60 4 "${W[@]}" 3>&2 2>&1 1>&3)

        if [ ! "$selection" ]; then
            break
        fi

        case $selection in
            1) koel_import_from_directory;;
            2) koel_import_from_usb;;
            3) koel_export_to_usb;;
            4) format_music_drive;;
        esac
    done
}

function upgrade_koel {
    if grep -q "koel domain" "$COMPLETION_FILE"; then
        KOEL_DOMAIN_NAME=$(get_completion_param "koel domain")
    fi

    CURR_KOEL_COMMIT=$(get_completion_param "koel commit")
    if [[ "$CURR_KOEL_COMMIT" == "$KOEL_COMMIT" ]]; then
        return
    fi

    systemctl stop koel

    # update to the next commit
    function_check set_repo_commit
    set_repo_commit "/var/www/$KOEL_DOMAIN_NAME/htdocs" "koel commit" "$KOEL_COMMIT" $KOEL_REPO

    cd "/var/www/${KOEL_DOMAIN_NAME}/htdocs" || exit 7345346358
    php artisan koel:init
    koel_remove_gravatar
    chown -R www-data:www-data "/var/www/${KOEL_DOMAIN_NAME}/htdocs/"*

    systemctl start koel
}


function backup_local_koel {
    KOEL_DOMAIN_NAME='koel'
    if grep -q "koel domain" "$COMPLETION_FILE"; then
        KOEL_DOMAIN_NAME=$(get_completion_param "koel domain")
    fi

    source_directory="/var/www/${KOEL_DOMAIN_NAME}/htdocs"
    if [ -d "$source_directory" ]; then
        systemctl stop koel

        dest_directory=koel
        function_check suspend_site
        suspend_site "${KOEL_DOMAIN_NAME}"

        function_check backup_directory_to_usb
        backup_directory_to_usb "$source_directory" "$dest_directory"

        function_check backup_database_to_usb
        backup_database_to_usb koel

        function_check restart_site
        restart_site

        systemctl start koel
    fi
}

function restore_local_koel {
    if ! grep -q "koel domain" "$COMPLETION_FILE"; then
        return
    fi
    KOEL_DOMAIN_NAME=$(get_completion_param "koel domain")
    if [ "$KOEL_DOMAIN_NAME" ]; then
        echo $"Restoring koel"
        systemctl stop koel

        temp_restore_dir=/root/tempkoel

        function_check koel_create_database
        koel_create_database

        restore_database koel "${KOEL_DOMAIN_NAME}"
        if [ -d $temp_restore_dir ]; then
            rm -rf $temp_restore_dir
        fi

        MARIADB_PASSWORD=$("${PROJECT_NAME}-pass" -u root -a mariadb)
        cd "/var/www/$KOEL_DOMAIN_NAME/htdocs" || exit 274825424
        sed -i "s|DB_PASSWORD=.*|DB_PASSWORD=$MARIADB_PASSWORD|g" .env
        MARIADB_PASSWORD=

        systemctl start koel
    fi
}

function backup_remote_koel {
    if grep -q "koel domain" "$COMPLETION_FILE"; then
        KOEL_DOMAIN_NAME=$(get_completion_param "koel domain")
        temp_backup_dir=/var/www/${KOEL_DOMAIN_NAME}/htdocs
        if [ -d "$temp_backup_dir" ]; then
            systemctl stop koel

            function_check suspend_site
            suspend_site "${KOEL_DOMAIN_NAME}"

            function_check backup_database_to_friend
            backup_database_to_friend koel

            echo $"Backing up Koel installation"

            function_check backup_directory_to_friend
            backup_directory_to_friend "$temp_backup_dir" koel

            function_check restart_site
            restart_site

            systemctl start koel
        else
            echo $"koel domain specified but not found in ${temp_backup_dir}"
        fi
    fi
}

function restore_remote_koel {
    if grep -q "koel domain" "$COMPLETION_FILE"; then
        echo $"Restoring koel"

        systemctl stop koel

        KOEL_DOMAIN_NAME=$(get_completion_param "koel domain")

        function_check koel_create_database
        koel_create_database

        function_check restore_database_from_friend
        restore_database_from_friend koel "${KOEL_DOMAIN_NAME}"
        if [ -d /root/tempkoel ]; then
            rm -rf /root/tempkoel
        fi

        MARIADB_PASSWORD=$("${PROJECT_NAME}-pass" -u root -a mariadb)
        cd "/var/www/$KOEL_DOMAIN_NAME/htdocs" || exit 53743682
        sed -i "s|DB_PASSWORD=.*|DB_PASSWORD=$MARIADB_PASSWORD|g" .env
        MARIADB_PASSWORD=

        systemctl start koel

        echo $"Restore of koel complete"
    fi
}

function remove_koel {
    if [ ${#KOEL_DOMAIN_NAME} -eq 0 ]; then
        return
    fi

    systemctl stop koel
    systemctl disable koel
    if [ -f /etc/systemd/system/koel.service ]; then
        rm /etc/systemd/system/koel.service
    fi
    systemctl daemon-reload

    function_check remove_nodejs
    remove_nodejs koel

    read_config_param "KOEL_DOMAIN_NAME"
    read_config_param "MY_USERNAME"
    echo "Removing $KOEL_DOMAIN_NAME"
    nginx_dissite "$KOEL_DOMAIN_NAME"
    remove_certs "$KOEL_DOMAIN_NAME"

    if [ -d "/var/www/$KOEL_DOMAIN_NAME" ]; then
        rm -rf "/var/www/$KOEL_DOMAIN_NAME"
    fi
    if [ -f "/etc/nginx/sites-available/$KOEL_DOMAIN_NAME" ]; then
        rm "/etc/nginx/sites-available/$KOEL_DOMAIN_NAME"
    fi
    function_check drop_database
    drop_database koel
    function_check remove_onion_service
    remove_onion_service koel ${KOEL_ONION_PORT}
    remove_app koel
    remove_completion_param install_koel
    sed -i '/koel/d' "$COMPLETION_FILE"
    remove_backup_database_local koel

    function_check remove_ddns_domain
    remove_ddns_domain "$KOEL_DOMAIN_NAME"
}

function install_koel_main {
    if [ ! "$KOEL_DOMAIN_NAME" ]; then
        echo $'No domain name was given for koel'
        exit 7359
    fi

    if [[ $(app_is_installed koel_main) == "1" ]]; then
        return
    fi

    function_check install_mariadb
    install_mariadb

    function_check get_mariadb_password
    get_mariadb_password

    function_check repair_databases_script
    repair_databases_script

    apt-get -yq install php-gettext php-curl php-gd php-mysql git curl php-zip
    apt-get -yq install php-memcached php-intl exiftool libfcgi0ldbl
    apt-get -yq install ffmpeg

    if [ ! -d "/var/www/$KOEL_DOMAIN_NAME" ]; then
        mkdir "/var/www/$KOEL_DOMAIN_NAME"
    fi
    if [ ! -d "/var/www/$KOEL_DOMAIN_NAME/htdocs" ]; then

        if [ -d /repos/koel ]; then
            mkdir "/var/www/$KOEL_DOMAIN_NAME/htdocs"
            cp -r -p /repos/koel/. "/var/www/$KOEL_DOMAIN_NAME/htdocs"
            cd "/var/www/$KOEL_DOMAIN_NAME/htdocs" || exit 23924295
            git pull
        else
            function_check git_clone
            git_clone "$KOEL_REPO" "/var/www/$KOEL_DOMAIN_NAME/htdocs"
        fi

        if [ ! -d "/var/www/$KOEL_DOMAIN_NAME/htdocs" ]; then
            echo $'Unable to clone koel repo'
            exit 365735
        fi
    fi

    cd "/var/www/$KOEL_DOMAIN_NAME/htdocs" || exit 834567242
    git checkout "$KOEL_COMMIT" -b "$KOEL_COMMIT"
    set_completion_param "koel commit" "$KOEL_COMMIT"

    chown -R www-data:www-data "/var/www/$KOEL_DOMAIN_NAME/htdocs"

    function_check koel_create_database
    koel_create_database

    function_check add_ddns_domain
    add_ddns_domain "$KOEL_DOMAIN_NAME"

    KOEL_ONION_HOSTNAME=$(add_onion_service koel 80 ${KOEL_ONION_PORT})

    koel_nginx_site=/etc/nginx/sites-available/$KOEL_DOMAIN_NAME
    if [[ $ONION_ONLY == "no" ]]; then
        function_check nginx_http_redirect
        nginx_http_redirect "$KOEL_DOMAIN_NAME" "index index.php"
        { echo 'server {';
          echo '  listen 443 ssl;';
          echo '  #listen [::]:443 ssl;';
          echo "  server_name $KOEL_DOMAIN_NAME;";
          echo ''; } >> "$koel_nginx_site"
        function_check nginx_compress
        nginx_compress "$KOEL_DOMAIN_NAME"
        { echo '    gzip_comp_level 9;';
          echo '';
          echo '  # Security'; } >> "$koel_nginx_site"
        function_check nginx_ssl mobile
        nginx_ssl "$KOEL_DOMAIN_NAME"

        function_check nginx_security_options
        nginx_security_options "$KOEL_DOMAIN_NAME"

        { echo '  add_header Strict-Transport-Security max-age=15768000;';
          echo '';
          echo '  # Logs';
          echo '  access_log /dev/null;';
          echo '  error_log /dev/null;';
          echo '';
          echo '  # Root';
          echo "  root /var/www/$KOEL_DOMAIN_NAME/htdocs;";
          echo '';
          echo '  # Index';
          echo '  index index.php;';
          echo '';
          echo '  # Whitelist only index.php, robots.txt, and those start with public/ or api/';
          echo "  if (\$request_uri !~ ^/\$|index\\.php|robots\\.txt|api/|public/) {";
          echo '    return 404;';
          echo '  }';
          echo '';
          echo '  location /media/ {';
          echo '    internal;';
          echo '';
          echo '    # A X-Media-Root should be set to media_path settings from upstream';
          echo "    alias       \$upstream_http_x_media_root;";
          echo '';
          echo '  }';
          echo '';
          echo '  # PHP';
          echo '  location ~ \.php {';
          echo '    include snippets/fastcgi-php.conf;';
          echo '    fastcgi_pass unix:/var/run/php/php7.0-fpm.sock;';
          echo '    fastcgi_read_timeout 30;';
          echo '  }';
          echo '';
          echo '  # Location';
          echo '  location / {'; } >> "$koel_nginx_site"
        function_check nginx_limits
        nginx_limits "$KOEL_DOMAIN_NAME" '15m'
        { echo "    try_files \$uri \$uri/ @koel;";
          echo '  }';
          echo '';
          echo '  # Fancy URLs';
          echo '  location @koel {';
          echo "    rewrite ^(.*)\$ /index.php?p=\$1 last;";
          echo '  }';
          echo '';
          echo '  # Restrict access that is unnecessary anyway';
          echo '  location ~ /\.(ht|git) {';
          echo '    deny all;';
          echo '  }';
          echo '';
          echo '}'; } >> "$koel_nginx_site"
    else
        echo -n '' > "$koel_nginx_site"
    fi
    if [[ "$ONION_ONLY" == 'no' ]]; then
        { echo 'server {';
          echo "    listen 127.0.0.1:$KOEL_ONION_PORT default_server;";
          echo "    server_name $KOEL_DOMAIN_NAME;";
          echo ''; } >> "$koel_nginx_site"
    else
        { echo 'server {';
          echo "    listen 127.0.0.1:$KOEL_ONION_PORT default_server;";
          echo "    server_name $KOEL_ONION_HOSTNAME;";
          echo ''; } >> "$koel_nginx_site"
    fi
    function_check nginx_compress
    nginx_compress "$KOEL_DOMAIN_NAME"
    { echo '    gzip_comp_level 9;';
      echo '';
      echo '  # Logs';
      echo '  access_log /dev/null;';
      echo '  error_log /dev/null;';
      echo '';
      echo '  # Root';
      echo "  root /var/www/$KOEL_DOMAIN_NAME/htdocs;";
      echo '';
      echo '  # Index';
      echo '  index index.php;';
      echo '';
      echo '  # Whitelist only index.php, robots.txt, and those start with public/ or api/';
      echo "  if (\$request_uri !~ ^/\$|index\\.php|robots\\.txt|api/|public/) {";
      echo '    return 404;';
      echo '  }';
      echo '';
      echo '  location /media/ {';
      echo '    internal;';
      echo '';
      echo '    # A X-Media-Root should be set to media_path settings from upstream';
      echo "    alias       \$upstream_http_x_media_root;";
      echo '';
      echo '  }';
      echo '';
      echo '  # PHP';
      echo '  location ~ \.php {';
      echo '    include snippets/fastcgi-php.conf;';
      echo '    fastcgi_pass unix:/var/run/php/php7.0-fpm.sock;';
      echo '    fastcgi_read_timeout 30;';
      echo '  }';
      echo '';
      echo '  # Location';
      echo '  location / {'; } >> "$koel_nginx_site"
    function_check nginx_limits
    nginx_limits "$KOEL_DOMAIN_NAME" '15m'
    { echo "    try_files \$uri \$uri/ @koel;";
      echo '  }';
      echo '';
      echo '  # Fancy URLs';
      echo '  location @koel {';
      echo "    rewrite ^(.*)\$ /index.php?p=\$1 last;";
      echo '  }';
      echo '';
      echo '  # Restrict access that is unnecessary anyway';
      echo '  location ~ /\.(ht|git) {';
      echo '    deny all;';
      echo '  }';
      echo '';
      echo '}'; } >> "$koel_nginx_site"

    sed -i 's|gzip_types.*|gzip_types text/plain text/css application/x-javascript text/xml application/xml application/xml+rss text/javascript application/json;|g' "$koel_nginx_site"
    sed -i 's|DENY;|SAMEORIGIN;|g' "$koel_nginx_site"

    function_check configure_php
    configure_php

    function_check create_site_certificate
    create_site_certificate "$KOEL_DOMAIN_NAME" 'yes'

    # Ensure that the database gets backed up locally, if remote
    # backups are not being used
    function_check backup_databases_script_header
    backup_databases_script_header

    function_check backup_database_local
    backup_database_local koel

    function_check nginx_ensite
    nginx_ensite "$KOEL_DOMAIN_NAME"

    systemctl restart mariadb
    systemctl restart php7.0-fpm
    systemctl restart nginx

    "${PROJECT_NAME}-pass" -u "$MY_USERNAME" -a koel -p "$KOEL_ADMIN_PASSWORD"

    set_completion_param "koel domain" "$KOEL_DOMAIN_NAME"

    install_completed koel_main
}

function install_koel {
    if [ ! $ONION_ONLY ]; then
        ONION_ONLY='no'
    fi

    function_check install_nodejs
    install_nodejs koel

    install_koel_main

    cd "/var/www/$KOEL_DOMAIN_NAME/htdocs" || exit 2432848
    install_composer

    npm install -g yarn
    npm install

    function_check get_mariadb_password
    get_mariadb_password

    cp .env.example .env
    sed -i "s/ADMIN_EMAIL=.*/ADMIN_EMAIL=$MY_EMAIL_ADDRESS/g" .env
    sed -i "s/ADMIN_NAME=.*/ADMIN_NAME=$MY_USERNAME/g" .env
    sed -i "s/ADMIN_PASSWORD=.*/ADMIN_PASSWORD=$KOEL_ADMIN_PASSWORD/g" .env
    sed -i 's/DB_CONNECTION=.*/DB_CONNECTION=mysql/g' .env
    sed -i 's/DB_HOST=.*/DB_HOST=127.0.0.1/g' .env
    sed -i 's/DB_DATABASE=.*/DB_DATABASE=koel/g' .env
    sed -i 's/DB_USERNAME=.*/DB_USERNAME=root/g' .env
    sed -i "s|DB_PASSWORD=.*|DB_PASSWORD=$MARIADB_PASSWORD|g" .env
    sed -i 's/MAIL_HOST=.*/MAIL_HOST=localhost/g' .env
    sed -i 's/MAIL_PORT=.*/MAIL_PORT=25/g' .env
    sed -i 's|FFMPEG_PATH=.*|FFMPEG_PATH=/usr/bin/ffmpeg|g' .env

    if ! php artisan koel:init; then
        echo $"Can't install koel:init"
        exit 78362
    fi
    koel_remove_gravatar
    chown -R www-data:www-data "/var/www/$KOEL_DOMAIN_NAME/htdocs"

    # daemon
    { echo '[Unit]';
      echo 'Description=Koel (music player)';
      echo 'After=syslog.target';
      echo 'After=network.target';
      echo '';
      echo '[Service]';
      echo 'Type=simple';
      echo 'User=www-data';
      echo 'Group=www-data';
      echo "WorkingDirectory=/var/www/$KOEL_DOMAIN_NAME/htdocs";
      echo "ExecStart=/usr/bin/php artisan serve --port=$KOEL_PORT";
      echo 'Restart=on-failure';
      echo '';
      echo '[Install]';
      echo 'WantedBy=multi-user.target'; } > /etc/systemd/system/koel.service
    systemctl enable koel.service
    systemctl daemon-reload
    systemctl start koel.service

    if [ ! -d /music ]; then
        mkdir /music
    fi
    chown -R www-data:www-data /music

    systemctl restart mariadb
    systemctl restart nginx

    APP_INSTALLED=1
}

# NOTE: deliberately there is no "exit 0"